In addition to building blocks and circulation system, there are open-green spaces in the cities. In these open-green spaces, there are such public, private or half-private areas as parks, squares, playgrounds and gardens of residences. The planning and design projects of these spaces are made by landscape architects. Designing process involves a few phases. These phases are survey, concept plan, preliminary design, final design, structural and planting landscape application projects and detail drawings. Besides, the explanation report is prepared after the design. Before the application of the designed projects, it is necessary to make quantity survey, price calculation and cost calculations. During these calculations, construction projects, detail projects and technical specifications are needed. In this context, the purpose of this study is to make the landscape design project, quantity survey, price calculation and approximate cost calculation of a building project in Yıldız district of Çankaya Municipality. Thus, those who demand a project will know the budget they should allocate and make their planning accordingly, before they application the project. As a result, this study will serve as a sample towards how to do approximate cost calculations today and contribute to the literature.